The structure-based development of inhibitors of key proteins of the human immunodeficiency virus (HIV) and of organisms responsible for HIV-related opportunistic infections is proposed. Despite the major advances made recently in the treatment of acquired immunodeficiency syndrome (AIDS) it remains a major threat to the public health. Furthermore, the widespread development of resistance to antibacterial and antiviral drugs, the emergence of new diseases, and the escalating costs of drug discovery and health care make the development of more rapid and efficient drug discovery methods imperative. The primary HIV targets to be used for the development of inhibitors are integrase, Rev, and previously unexplored sites on reverse transcriptase. A dominant negative approach to inhibition of the HIV protease will also be pursued. In addition, two discovery efforts will focus on protein targets of HIV-related opportunistic infections: (a) the protease of HHV8, the Kaposi's sarcoma virus, and (b) the Mycobacterium tuberculosis alkylhydroperoxidase. The alkylhydroperoxidase compensates for loss of the katG peroxidase in isoniazid resistant strains and is a new and exciting target for the treatment of drug resistant tuberculosis. The proteins required for these studies are currently produced by recombinant methods and are to be purified, crystallized, and subjected to X-ray diffraction analysis. Mechanistic studies of the less well characterized enzyme targets will be carried out to obtain the information required for the design of reversible and irreversible inhibitors. Structural and mechanistic information will be used in conjunction with computational methods to identify potential inhibitors of the enzymes. The inhibitor candidates will be synthesized, assayed with isolated enzymes, and in some cases co-crystallized with the enzymes for structural analysis. Inhibitor optimization will be assisted by computational approaches, and the improvement of such approaches for the discovery and optimization of drug candidates is one of the goals of this proposal. Promising drug candidates will be evaluated in cell culture and in vivo. This broad, structure-based attack on HIV and two major opportunistic infections should produce not only potentially useful drug leads but also fundamental knowledge relevant to the design of drugs for infectious agents.